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1   /*
2    * Copyright (C) 2010, Google Inc.
3    * and other copyright owners as documented in the project's IP log.
4    *
5    * This program and the accompanying materials are made available
6    * under the terms of the Eclipse Distribution License v1.0 which
7    * accompanies this distribution, is reproduced below, and is
8    * available at http://www.eclipse.org/org/documents/edl-v10.php
9    *
10   * All rights reserved.
11   *
12   * Redistribution and use in source and binary forms, with or
13   * without modification, are permitted provided that the following
14   * conditions are met:
15   *
16   * - Redistributions of source code must retain the above copyright
17   *   notice, this list of conditions and the following disclaimer.
18   *
19   * - Redistributions in binary form must reproduce the above
20   *   copyright notice, this list of conditions and the following
21   *   disclaimer in the documentation and/or other materials provided
22   *   with the distribution.
23   *
24   * - Neither the name of the Eclipse Foundation, Inc. nor the
25   *   names of its contributors may be used to endorse or promote
26   *   products derived from this software without specific prior
27   *   written permission.
28   *
29   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
30   * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
31   * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
34   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
35   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
36   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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38   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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40   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
41   * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
42   */
43  
44  package org.eclipse.jgit.revwalk;
45  
46  import java.io.IOException;
47  
48  import org.eclipse.jgit.diff.DiffConfig;
49  import org.eclipse.jgit.errors.IncorrectObjectTypeException;
50  import org.eclipse.jgit.errors.MissingObjectException;
51  import org.eclipse.jgit.treewalk.TreeWalk;
52  import org.eclipse.jgit.treewalk.filter.PathFilter;
53  import org.eclipse.jgit.treewalk.filter.TreeFilter;
54  
55  /**
56   * Updates the internal path filter to follow copy/renames.
57   * <p>
58   * This is a special filter that performs {@code AND(path, ANY_DIFF)}, but also
59   * triggers rename detection so that the path node is updated to include a prior
60   * file name as the RevWalk traverses history.
61   *
62   * The renames found will be reported to a
63   * {@link org.eclipse.jgit.revwalk.RenameCallback} if one is set.
64   * <p>
65   * Results with this filter are unpredictable if the path being followed is a
66   * subdirectory.
67   */
68  public class FollowFilter extends TreeFilter {
69  	/**
70  	 * Create a new tree filter for a user supplied path.
71  	 * <p>
72  	 * Path strings are relative to the root of the repository. If the user's
73  	 * input should be assumed relative to a subdirectory of the repository the
74  	 * caller must prepend the subdirectory's path prior to creating the filter.
75  	 * <p>
76  	 * Path strings use '/' to delimit directories on all platforms.
77  	 *
78  	 * @param path
79  	 *            the path to filter on. Must not be the empty string. All
80  	 *            trailing '/' characters will be trimmed before string's length
81  	 *            is checked or is used as part of the constructed filter.
82  	 * @param cfg
83  	 *            diff config specifying rename detection options.
84  	 * @return a new filter for the requested path.
85  	 * @throws java.lang.IllegalArgumentException
86  	 *             the path supplied was the empty string.
87  	 * @since 3.0
88  	 */
89  	public static FollowFilter create(String path, DiffConfig cfg) {
90  		return new FollowFilter(PathFilter.create(path), cfg);
91  	}
92  
93  	private final PathFilter path;
94  	final DiffConfig cfg;
95  
96  	private RenameCallback renameCallback;
97  
98  	FollowFilter(PathFilter path, DiffConfig cfg) {
99  		this.path = path;
100 		this.cfg = cfg;
101 	}
102 
103 	/** @return the path this filter matches. */
104 	/**
105 	 * Get the path this filter matches.
106 	 *
107 	 * @return the path this filter matches.
108 	 */
109 	public String getPath() {
110 		return path.getPath();
111 	}
112 
113 	/** {@inheritDoc} */
114 	@Override
115 	public boolean include(TreeWalk walker)
116 			throws MissingObjectException, IncorrectObjectTypeException,
117 			IOException {
118 		return path.include(walker) && ANY_DIFF.include(walker);
119 	}
120 
121 	/** {@inheritDoc} */
122 	@Override
123 	public boolean shouldBeRecursive() {
124 		return path.shouldBeRecursive() || ANY_DIFF.shouldBeRecursive();
125 	}
126 
127 	/** {@inheritDoc} */
128 	@Override
129 	public TreeFilter clone() {
130 		return new FollowFilter(path.clone(), cfg);
131 	}
132 
133 	/** {@inheritDoc} */
134 	@SuppressWarnings("nls")
135 	@Override
136 	public String toString() {
137 		return "(FOLLOW(" + path.toString() + ")" //
138 				+ " AND " //
139 				+ ANY_DIFF.toString() + ")";
140 	}
141 
142 	/**
143 	 * Get the callback to which renames are reported.
144 	 *
145 	 * @return the callback to which renames are reported, or <code>null</code>
146 	 *         if none
147 	 */
148 	public RenameCallback getRenameCallback() {
149 		return renameCallback;
150 	}
151 
152 	/**
153 	 * Sets the callback to which renames shall be reported.
154 	 *
155 	 * @param callback
156 	 *            the callback to use
157 	 */
158 	public void setRenameCallback(RenameCallback callback) {
159 		renameCallback = callback;
160 	}
161 }